Multizone variable damper for use in an air passageway

ABSTRACT

A multizone variable damper for air passageways having a plurality of damper zones, a plurality of opposed blades that are rotatable about a horizontal axis, a pair of blades of the plurality of blades being provided in each zone of the plurality of damper zones, and an actuator for each pair of blades, each actuator being configured to independently rotate each of the pairs of blades of the plurality of opposed blades so as to selectively and independently control a degree of openness of each of the pairs of blades of the plurality of opposed blades in each damper zone of the plurality of damper zones.

BACKGROUND

1. Field of the Invention

This invention relates to variable dampers that regulate air flow through passageways, such as grates. The dampers are positioned in or adjacent the passageways and have one or more members that selectively and variably block air passing through the passageways.

2. Background of the Invention

There are certain environments in which it may be desirable to regulate the air flow through a passageway such that different volumes of air are permitted to pass through different zones of the passageway. One such environment is a data center, and the subject passageway is an access floor grate panel in the data center, as discussed below.

A typical data center includes multiple IT racks. The equipment supported by those racks, and the associated cables and other accessories, generate a relatively high amount of heat. Because of that heat, providing adequate cooling to IT racks in the data center is of paramount importance. Moreover, it is desirable that the IT racks be cooled as efficiently as possible, as the energy costs to cool IT racks may approach a large percentage of the energy costs to operate the data center.

Data centers typically have a raised floor system, often called an access floor system. An access floor system is usually comprised of a continuous array of floor panels, arranged edge-to-edge, and supported above the sub-floor by support structure. The array of access floor panels usually extends wall-to-wall in the data centers.

A plenum is formed between the sub-floor and the access floor panel array. Cables, wires, hoses, etc. are located in the plenum, and the plenum is also used as a conduit for cooling air. Often, one or more air conditioning units supply air to the plenum, and some of the access floor panels in the access floor panel array have grates. The cooling air passes through the grates into the data center.

The access floor panels with grates are usually positioned immediately adjacent to IT racks, and may have vanes that direct the cooling air that passes through the grates toward the IT racks.

A typical IT rack supports a variety of electronic equipment. The equipment is often unevenly distributed throughout the rack, including vertically. In that regard, an IT rack may have shelves, spaced vertically. Different equipment may be placed on the different individual shelves.

Different IT equipment generates different amounts of heat. Thus, the heat generated by the equipment at one vertical height of an IT rack (e.g., on one shelf) may differ from the heat generated by the equipment at another vertical height of the same IT rack (e.g., on a different shelf). However, the prior art IT rack cooling apparatus does not take into account that difference in heat at the various heights. Rather, usually there are temperature sensors at various locations of an IT rack, and the volume of cooling air is determined for the whole rack based on the readings of those sensors. In fact, often the volume of cooling air for the entire rack is based on the highest sensed temperature in the IT rack. That is, the entire IT rack is subjected to the volume of cooling air necessary to cool the hottest area or zone in the rack, even the areas or zones of the rack that are already much cooler than the hottest area or zone.

This results in inefficient cooling of the IT racks, because the cooling air is directed at the same volume to all areas of the IT rack based on the highest temperature in the rack, even to those areas that may need little, if any, cooling. More efficient and economical cooling would be achieved if larger amounts of cooling air are directed to the hottest areas of the IT racks, while lesser amounts of cooling air are directed to the other, cooler areas of the IT rack. Thus, in a data center, there is a need for cooling apparatus that directs different amounts of cooling air to different areas of or zones in the IT racks in the data center.

SUMMARY OF THE INVENTION

The multizone variable damper of this invention addresses that need, as well as the need in other environments for apparatus that selectively regulates the flow of air in different zones of a passageway.

A multizone variable damper according to one embodiment of this invention includes two or more air passageway zones defined by movable members, wherein the positions of the movable members determine the air passageway openings in each of the passageway zones. The movable members are movable relative to each other such that the sizes of the air passageway openings in the passageway zones can be varied relative to each other. This embodiment also includes actuators that move the movable members relative to each other.

In certain embodiments, the movable members are pairs of opposed blades, with one of the pairs of opposed blades being located in each air passageway zone. The blades may extend lengthwise, and the air passageway zones may be aligned edge-to-edge widthwise.

The actuators can be manual or “automatic.” The “automatic” actuators may move the movable blades based on predetermined conditions (e.g., time of day) or sensed conditions (e.g., temperature or pressure differential).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial view of a data center that includes a multizone variable damper of this invention.

FIG. 2 is a top view of one embodiment of this invention.

FIG. 3 is a side view of the embodiment of this invention illustrated in FIG. 2.

FIG. 4 is a schematic diagram of the multizone variable damper of FIGS. 1-3 installed in an access floor panel array, with temperature sensors on the adjacent IT rack.

FIG. 5 is a schematic diagram of the sensors, control unit and actuators.

FIGS. 6 and 7 illustrate the multizone variable damper of FIGS. 2 and 3, in a data center, with the pairs of opposing blades in different positions.

DETAILED DESCRIPTION

Before describing the multizone variable damper of this invention, one environment in which it may be utilized is first described. The environment is a data center that includes one or more IT racks. That environment is illustrated, in part, in FIG. 1.

In FIG. 1, IT rack 30 is in a data room and positioned on and supported by access floor panel array 35. Access floor array 35 is spaced above subfloor 34. The space or plenum 70 between access floor panel array 35 and subfloor 34 functions as a conduit for air from an air conditioning unit (not shown). The access floor panel array 35 includes grate panel 32, which is positioned immediately adjacent IT rack 30. An access floor panel array in a data room will usually include multiple grate panels. FIG. 1 illustrates one of those grate panels. Cooling air passes from plenum 70 through grate panel 32 to cool IT rack 30.

IT rack 30 supports a variety of IT equipment. The heat generated by the equipment supported by IT rack 30 may vary in different areas or zones of IT rack 30 for many reasons, including the following. First, different types of IT equipment generate different amounts of heat. Second, the equipment may be unevenly distributed in IT rack 30, in all three dimensions, including vertically, laterally and longitudinally. Third, different units or assemblies of the equipment may operate at different times of the day. All of those factors may result in zones of different temperatures in IT rack 30 at any given time. For example, in FIG. 1, IT rack 30 may have vertical zones 31 a, 31 b and 31 c, from bottom to top, of different temperatures at a given time. In FIG. 1, those temperatures are: zone 31 a—73°; zone 31 b—75°; and zone 31 c—71°.

To achieve the most efficient and economical cooling of IT rack 30 when it has zones of different temperatures, such as zones 31 a, 31 b and 31 c, it is desirable to supply or direct different volumes of cooling air to the different zones, so that each zone is cooled by the minimum necessary amount of cooling air. Thus, taking FIG. 1 as an example, for efficient and economical cooling, more cooling air should be directed to zone 31 b than to zones 31 a and 31 c, and more cooling air should be directed to zone 31 a than to zone 31 c.

This invention achieves that goal, as discussed in detail below.

The embodiment of this invention illustrated in the Figures is multizone variable damper 10. In FIG. 1, multizone variable damper 10 is positioned below grate panel 32 in access floor panel array 35.

Multizone variable damper 10 is illustrated in more detail in FIGS. 2 and 3. In particular, FIG. 2 is a top view and FIG. 3 is a side view of multizone variable damper 10.

In the embodiment illustrated in the Figures, the multizone variable damper 10 defines three zones: zones 21 a, 21 b and 21 c. The number of zones is not limited to three, but can be more than three zones and as few as two zones.

The zones 21 a, 21 b and 21 e are positioned such that air that passes through each zone is directed, by grate panel 32, to a specific zone in IT rack 30. In this embodiment, the air from zone 21 a is directed to IT rack zone 31 a, the air from zone 21 b is directed to IT rack zone 31 b, and the air from zone 21 c is directed to IT rack zone 31 c. See FIGS. 6 and 7, discussed in more detail below.

Also in the embodiment illustrated in the Figures, each zone has a pair of opposed blades that move relative to each other to control airflow through that zone. Specifically, opposed blades 30 a are in zone 21 a, opposed blades 30 b are in zone 21 b and opposed blades 30 c are in zone 21 c. The blades 30 a, 30 b and 30 c can be made of any material that is capable of providing the structural rigidity required for a given application. Preferably, the blades 30 a, 30 b and 30 c are made of metal.

Opposed blades 30 a, 30 b and 30 c extend the length of multizone variable damper 10, and the zones 21 a, 21 b and 21 e are located serially along the width of multizone variable damper 10.

As shown in FIG. 3, in this embodiment of the invention, each blade of blades 30 a, 30 b and 30 c is rotatable about an axis. The blades are rotatable between the extreme positions of completely closed (see blades 30 a in FIG. 3) to completely open (see blades 30 c in FIG. 3) to all positions between those extreme positions.

While the embodiment illustrated in the Figures utilizes pairs of opposed blades 30 a, 30 b and 30 c to regulate the amount of air that passes through each zone 21 a, 21 b and 21 c, respectively, any other means for variably regulating air flow through zones 21 a, 21 b and 21 c can be used in place of opposed blades 30 a, 30 b and 30 c, including single blades. However, one advantage of using a pair of opposed blades instead of a single blade is that the pair of opposed blades does not interfere with the directional nature of grate panel 32 if grate panel 32 is a directional grate.

In this embodiment, the multizone variable damper 10 includes actuators 20 a, 20 b and 20 c, which are provided for each pair of opposed blades 30 a, 30 b, and 30 c, respectively. The actuators 20 a, 20 b and 20 c rotate the pairs of opposed blades 30 a, 30 b and 30 c to their desired positions. The actuators 20 a, 20 b and 20 c can either be manually operated or can be automatically operated.

There is a wide variety of manual actuators that can be used to rotate the blades of pairs of opposed blades 30 a, 30 b and 30 c, including a lever (not shown) that is rotatable between fully closed and fully opened positions, and all positions between those two extremes. The lever is connected by a link or a series of links to a member that rotates the pair of blades. When the lever is in a first position, the rotatable member positions the pair of blades in the completely closed position. When the lever is rotated to a second position, the rotatable member is rotated to position the pair of blades in the completely open position.

There is also a wide variety of “automatic” actuators that can be used to rotate the blades of pairs of opposed blades 30 a, 30 b and 30 c, including motors that rotate the blades in accordance with signals or instructions from a control unit. The control unit may instruct the movement of the blades based on a sensed condition, or a predetermined condition such as by the time. An example of a control unit that is responsive to a sensed condition is illustrated in FIG. 5.

In FIG. 5, the temperatures from sensors 80 a, 80 b and 80 c are communicated to control unit 110. Based on that temperature data, control unit 110 instructs the actuators 20 a, 20 b and 20 c to rotate the various blades of pairs of blades 30 a, 30 b and 30 e as necessary to adjust the openings provided by the pairs of blades 30 a, 30 b and 30 c.

In the embodiment illustrated by FIG. 4, the temperature sensors 80 a, 80 b and 80 c are located in IT rack zones 31 a, 31 b and 31 c, respectively. Each sensor 80 a, 80 b and 80 c can be a single sensor unit or multiple sensor units. In the embodiment illustrated in the FIG. 4, the temperature sensors 80 a, 80 b and 80 c are single units located on the front face 100 of the IT rack 30. However, the temperature sensors 80 a, 80 b and 80 c can be placed at other positions in zones 31 a, 31 b and 31 c, for example, on the back face of IT rack 30 where the cooling air is exhausted. Further, if a sensor 80 a, 80 b and/or 80 c includes more than one sensor unit, those sensor units can be positioned in different locations in the respective zones 31 a, 31 b and 31 c.

The temperature data from sensors 80 a, 80 b and 80 c is used to adjust the positions of the blades of pairs of blades 30 a, 30 b and 30 c so that the minimal necessary cooling air is directed or supplied to the IT rack zones 31 a, 31 b and 31 c. Examples are discussed below, with reference to FIGS. 6 and 7.

In FIG. 6, the temperature in IT rack zone 31 a is 73°, the temperature in IT rack zone 31 b is 75°, and the temperature in IT rack zone 31 c is 71°. Those temperatures are communicated to control unit 110, which instructs actuators 20 a, 20 b and 20 c to place blades 30 a, 30 b and 30 c in the positions illustrated in FIG. 6, which is that blades 30 a are in a partially open state, blades 30 b are in a fully opened state and blades 30 c are in a completely closed state. This results in the highest airflow being directed to IT rack zone 31 a, a less amount of airflow being directed to IT rack zone 31 b, and little, if any, airflow being directed to IT rack zone 31 c.

In FIG. 7, the temperature in IT rack zone 31 a is 74°, the temperature in IT rack zone 31 b is 73°, and the temperature in IT rack zone 31 c is 71°. Accordingly, control unit 110 instructs actuators 20 a, 20 b and 20 c to rotate blades 30 a and 30 b such that blades 30 a and 30 b are positioned to be partially open; however, the opening through blades 30 a is greater than the opening through blades 30 b because IT rack zone 30 a is warmer than IT zone 31 b. Finally, the blades 30 e are positioned in the completely closed position.

As can be determined, blades 30 a, 30 b and 30 c can be positioned relative to each other in any manner dictated by the respective temperatures in IT rack zones 31 a, 31 b and 31 c.

As stated, in this embodiment, the control unit 110 controls the actuators 20 a, 20 b and 20 c based on temperatures in the respective IT rack zones, zones 31 a, 31 b and 31 c. In other embodiments, the control unit 110 may receive and act on pressure differentials in the various zones, for example at the back face of the IT rack 30, instead of the temperatures.

Further, in other embodiments, each actuator 20 a, 20 b and 20 c may be operated by a separate control unit dedicated to it. That is, instead of a single control unit 110, there is a separate control unit for each actuator 20 a, 20 b and 20 c. Those individual control units receive information from the corresponding IT rack zones and provide instructions to the corresponding actuators. For example, an individual control unit for actuator 20 a would receive the temperature data from sensor 80 a and instruct actuator 20 a accordingly, the control unit for actuator 20 b would receive the temperature data from sensor 80 b and instruct actuator 20 b accordingly, and the control unit for actuator 20 c would receive temperature data from sensor 80 c and instruct actuator 20 c accordingly.

By providing three or more zones, the multizone variable damper 10 of this invention allows for precise cooling of the IT rack 30 based on sensed conditions along the height of the IT rack 30.

What has been described and illustrated herein are preferred embodiments of the invention along with some variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated. 

1. A multizone variable damper comprising: two or more air passageway zones defined by movable members, the positions of the movable members determining an air passageway opening in each of the two or more air passageway zones; the movable members being movable relative to each other such that the size of the air passageway opening in each of the two or more air passageway zones can be different than the size of the air passageway opening in the other of the two or more air passageway zones; and actuators that move the movable members relative to each other.
 2. A multizone variable damper according to claim 1, wherein the movable members are pairs of rotatable opposed blades, and one of the pairs of rotatable opposed blades is located in each of the two or more air passageway zones.
 3. A multizone variable damper according to claim 2, wherein the pairs of rotatable opposed blades extend lengthwise in each of the two or more air passageway zones; and the two or more air passageway zones are aligned edge-to-edge widthwise.
 4. A multizone variable damper according to claim 3, wherein the actuators are manual actuators.
 5. A multizone variable damper according to claim 3, wherein the actuators are automatic actuators that move the movable members based on a sensed condition.
 6. A multizone variable damper according to claim 5, wherein the sensed condition is temperature.
 7. A multizone variable damper according to claim 3, wherein the actuators are automatic actuators that move the movable members based on a predetermined condition.
 8. A multizone variable damper comprising; a plurality of pairs of opposed blades, each of the opposed blades being rotatable about a horizontal axis; the opposed blades running lengthwise of the damper and the pairs of opposed blades being arranged edge to edge along the width of the damper; and an actuator provided for each of the pairs of opposed blades and being configured to independently rotate each of the pairs of opposed blades of the plurality of opposed blades so as to selectively and independently control a degree of openness of each of the pairs of opposed blades of the plurality of opposed blades.
 9. The multizone variable airflow damper according to claim 8, further comprising: one or more control units that control the actuators to adjust the degree of openness of each pair of opposed blades of the plurality of pairs of opposed blades.
 10. The multizone variable airflow damper according to claim 9, wherein the control unit controls the actuators based on a sensed condition.
 11. The multizone variable airflow damper according to claim 10, wherein the sensed condition is temperature.
 12. A method of providing cooling air to an IT rack through an access floor grate panel, the method comprising: providing a multizone variable damper below the access floor grate panel having: a plurality of pairs of opposed blades, each of the opposed blades being rotatable about a horizontal axis; the opposed blades running lengthwise of the damper and the pairs of opposed blades being arranged edge to edge along the width of the damper; an actuator provided for each of the pairs of opposed blades and being configured to independently rotate each of the pairs of opposed blades of the plurality of opposed blades so as to selectively and independently control a degree of openness of each of the pairs of blades of the plurality of opposed blades; and individually controlling the degree of openness of each of the pairs of blades of the plurality of opposed blades based on sensed conditions at specific locations along a height of the IT rack.
 13. A method of providing cooling air to an IT rack through an access floor grate panel according to claim 12, wherein the sensed conditions are temperature.
 14. A method of providing cooling air to an IT rack through an access floor grate panel according to claim 12, wherein the sensed conditions are pressure differential.
 15. A multizone variable damper for use with an access floor grate panel comprising: a plurality of movable blades, wherein one or more of the plurality of blades define different zones in which the air flow therethrough can vary depending on the position of the one or more blades; the blades extending lengthwise and the zones being serially located edge to edge widthwise; a plurality of actuators that are operable to adjust positions of the blades independently from blades in a different zone; and the damper being positionable below the access floor grate panel.
 16. A multizone variable air damper for use with an access floor grate panel comprising: a plurality of blades and actuators with the position of at least one blade of the plurality of blades being controlled by each of the actuators; the blades extending lengthwise and the plurality of blades being arranged serially along the width of the damper; the actuators being operable to adjust the position of the blades independently of the other blades; and the damper being positionable below the access floor grate panel.
 17. A multizone variable damper for use with a grate in an access floor panel, comprising: two or more air passageway zones defined by movable members, the positions of the movable members determining an air passageway opening in each of the two or more air passageway zones; the movable members being movable relative to each other such that the size of the air passageway opening in each of the two or more air passageway zones can be different than the size of the air passageway opening in the other of the two or more air passageway zones; and actuators that move the movable members relative to each other; wherein the multizone variable damper is positionable immediately below the grate.
 18. A multizone variable damper according to claim 17, wherein the movable members are pairs of rotatable opposed blades, and one of the pairs of rotatable opposed blades is located in each of the two or more air passageway zones.
 19. A multizone variable damper according to claim 18, wherein the pairs of rotatable opposed blades extend lengthwise in each of the two or more air passageway zones; and the two or more air passageway zones are aligned edge-to-edge widthwise.
 20. A multizone variable damper according to claim 19, wherein the actuators are automatic actuators that move the movable members based on a sensed condition. 